The county taxes are set by the county government. If your county government is taxing you too much, you should elect people who will not tax you that much. But electing Republicans just because they are Republicans isn't going to do it, anymore. Today's Republicans seem to love tax money even more than Democrats do.
If a county requires $100,000,000 dollars to run, and has 50,000 houses with a market value of $100,000 each, it can raise the required money by taxing the houses at 2% of the market value, or $2,000 each.
Now if the market value of houses doubles to $200,000 each, the amount of money it requires to run the county does not necessarily change. The county still needs $100,000,000, and can raise that money by taxing houses at 1% of the market value, or $2,000 each.
So if the County Assessor is going to reassess properties to reflect the current market value, the county government should reduce the property tax rate to compensate, so no excess money is taken. If they aren't doing this, the citizens should be rightly outraged, and replace them with politicians who will.
Alternatively, the County Assessor could not reassess properties to reflect the current market value, but rather use a formula that is not market based. That way there is no need to change tax rates to reflect fluctuating market conditions.
Where can I get some of these politicians who will act like that? They are in short supply around here. ;-)